Biovest International Inc. said it will market its personalized cancer vaccine for a third type of non-Hodgkin’s lymphoma.

Biovest’s vaccine has been granted seven years of U.S. market exclusivity for Waldenstrom’s macroglobulinemia, a rare type of non-Hodgkin’s lymphoma.

Biovest has already received similar market exclusivity for follicular and mantle cell lymphomas, other types of non-Hodgkin’s lymphoma.

Doctors diagnose about 1,500 cases of Waldenstrom’s macroglobulinemia each year in the nation, Tampa-based Biovest said. The disease is a slow-growing cancer that impacts the patient’s immune system.

The exclusivity will start after Biovest receives regulatory approval from the U.S. Food and Drug Administration. The company said it expects to file its application for the approval next year.

Biovest’s vaccine, called BiovaxID, is custom-made for each patient and is used after chemotherapy. The company says the vaccine would help prevent the cancer cells from returning. Biovest plans to manufacture the vaccine in Minnesota.

Here’s how the treatment works: Each patient’s lymphoma cells have an identifying protein not present in healthy cells. Biovest receives a small sample of the patient’s cancer cells through a biopsy. Then, it extracts the identifying protein and multiplies it through a special machine. Biovest links the protein with a foreign shellfish protein to make the vaccine. The body recognizes the vaccine as an invader and begins to attack and kill not only the injected vaccine, but also all lymphoma cells in the body. The body is then prepared to kill any future lymphoma cells. The treatment is given through a series of five vaccinations over a six-month period.

 Biovest hasn’t disclosed the retail price of its vaccine, but if it is priced similar to other personalized cancer vaccines in the market, it could cost tens of thousands of dollars.